Gear



A. SUNDH.

GEAR. APPLlcA'Uon man Aue. s. 191'8.

lPatented Feb. 1, 192,1.

Secnon A-A /0 SEcTlou B -B- Fig.` 4

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A TTUHNEY l so .AUGUST SUNIJI, 0F HSIINGS-UPON-HUDSON, NEW YORK.

enna.

Specification ot' Letters Patent.

Patented nel). 1, 1921.

App1ication led August 6, 1918. Serial No. 248,523.

To ad fw hoff/t may concer/a:

Be it known that I, Anous'r SUNDH, a citizen of the United States, residing at Hastings-upon--IIudson, in the county of Filestchester and State of New York, have invented certain new and 'useful Improvements in Gears, which the following is a full, clear, and exact specification.

My invention relates to an improvement in gears with particular reference to the construction of the gear, itself, it being an object of the present invention to provide gears which will run practically free from noise. To this end, therefore, in carrying out my invention I take a hollow member, cut teeth in the surface of the saine and then slot it spirally so that in reality the gear has the appearance of a toothed spiral spring. This member is then mounted upon a drive shaft, each end of the toothed mem ber being preferably rigidly secured to the shaft, but that portion of the gear between the ends thereof is spaced from the drive shaft, so as to yield inwardly under pressure.

It will be seen that when the gear is iounted on its drive shaft that the driving surface is free to yield in all directions and each tooth of the gear being' divided into several parts, the tooth is free to accom modate itself under tension to any irregularities there may be in a gear meshing with my improved construction, to insure practically a perfect mesh at all times, and thereby providing not only a more eiiicient but a comparatively quieter drive.

Referring to the accompanying drawings,

Figures l, 2 and 3 show an embodiment of my invention in end elevation, side elevation and cross section, respectively-Fig.`

3 being a section on the line AMA. of Fig. 1.

Figs. 4 and 5 show a modified form of my invention in end and side sectional elevational views, respectively ;-Fig. 5 being a section taken on the line B-B of Fig. L1.

Referring to the drawings in detail, with particular reference to Figs. 1, 2 and 3, 1 designates a shaft on which improved gear 2 is mounted. The `gear 2 comprises a hollow member having a continuous spiral slot cut through the walls thereof to form spiral convolutions 3. On the surface of this member I cut the teeth f1 of the gea-r. I prefer to have any one lfear tooth divided between several of the convolutions 3. In other words, the tooth of a gear 5 will mesh `riphery of the shaft 1, to permit. the gear teeth to yield inwardly. It will beapparn ent that in operation all portions of a gear tooth in the gear 2 are free to yield not only as a unit but as several units, so that any irregularities in the teeth of the gear 5 or the gear 2 will be accommodated to cause the gears at all times to mesh perfectly to eliminate chattering and other objectionable noises.

The modified construction of Figs. 4 and 5 is the same in principle as that just described, the only difference being that I have provided in this instance an internal toothed gear. In this form of my invention 8 designates a gear housing mounted on a drive shaft 9, a gear 10 being mounted on the shaft 9 and within the housing 8, this gear corresponding to the gear of Fig. 1, and differing therefrom only in that it is internally toothed, as shown `at 11. These teeth mesh with a gear 12 mounted on a shaft 13. As before, the gear 10 is rigidly secured to the shaft 9. clearance space has been provided between the outer face of the gear 10 and the inner face of the housing 8 to permit the teeth to yield outwardly. It will be apparent that the performance of this gear, so far as noise is concerned, will be on all fours with that of Figs. 1, 2 and 3, inasmuch as the gear is made in the same way, except as already noted. y

From the foregoing it will be seen that I have provided a gear construction which is practically noiseless when transmitting power, and which differs from all othel` gears for this purpose by reason of each tooth being split into several sections, which are movable independently of each other, so that the gear as a whole when in mesh with the usual type of gear will accommodate itself to any irregularities there may be, either in its own teeth or in those of the gear with which it may be in mesh.

It is to be understood that I do not limit myself to a gear comprising a hub having a spiral slot cut therein inasmuch, as it 1s VWithin the scope of my invention to substitute the hub With an iron or steel bar closely Wound in spiral form, across the vface of which I Will cut the gear teeth. Similarly it is to be understood that I do not confine myself to the other specific details of construction, but should be limited only by the scope of the appended claims and equivalent structures. n

What I claim as new, is:

l. As an article of manufacture, a hollow `member having a spiral out through the Walls thereof to form a resilient member and gear teeth formed on the periphery of the convolutions of the resilient member, the convolutions of the spiral being spaced apartv throughout their extent.

2. A'gear structure comprising a hollow member having spiral convolutions on which are formed gear teeth, the hollow member having some of its convolutions positively connected to a drive shaft on which the gear is mounted.

3. A gear structure comprising a hollow member having spiral convolutions on which are formed the gear teeth, portions of the convolutions of the gear being positively connected to a drive shaft on which the gear is mounted, to leave the remaining portions free to yield relatively to each other and to the drive shaft.

4. A gear structure comprising a spiral spring member having gear teeth formed in the convolutions thereof and longitudinally of the member, the ends of said member being rigidly secured to a drive shaft leaving the remaining portion of the convolutions free to yield relatively to each other and to the drive shaft.

AUGUST SUNDH 

